JPS61183614A - Wafer inspecting microscope device - Google Patents

Abstract

PURPOSE:To reduce a variation quantity of an optical path length by executing an inspecting operation by a one-dimensional movement of an objective optical system, and a one-dimensional movement or a rotational motion of a stage, or a rotational motion centering around an eyepiece part optical axis of the objective optical system. CONSTITUTION:In a wafer inspecting microscope device in which an objective optical system 18 is moved along the upper face of a wafer 10, an inspecting operation of the wafer surface by the objective optical system 18 is executed by a one-dimensional movement of the objective optical system 18, for instance, the movement of the diameter direction of the wafer 10, and a one-dimensional movement or a rotational motion of a wafer inspecting stage 7, or a rotational motion centering around an eyepiece part optical axis of the objective optical system 18.

Description

[Detailed description of the invention] And Dozumi The present invention relates to a wafer inspection microscope apparatus.

Eyebrow-LIL For example, the patent application filed earlier by the applicant in 1988-1292
The microscope described in No. 04 fixes a wafer to be inspected,
Is it possible to move the objective optical system YV along the top surface of the wafer? It was configured to inspect the surface of the wafer in the X and Y directions, but it was more compact than the one that moved the wafer in the X and Y directions. On the other hand, there is a drawback that the amount of change in the optical path length of the observation optical system is large, as described below. That is, as shown in FIG. 6, the change in optical path length in the X-axis direction and the Y-axis direction when the objective optical system moves from the position a closest to the origin 0 to the farthest position on the wafer 10 with a diameter R The amount is □R, so the amount of change in the overall optical path length is ffR, which is quite large. Therefore, if this microscope is an afocal type, the pupil is likely to be vignetted, so it is necessary to In order to prevent this, a large imaging lens is required,
There is also a problem in that the eye point position of the eyepiece lens moves significantly.

In view of the above-mentioned problems, the present invention maintains the advantage that the entire device can be made compact, and by reducing the amount of change in the optical path length, the pupil is less likely to be distorted even in the case of an afocal system. It is an object of the present invention to provide a wafer inspection microscope device in which the displacement of the operator is also reduced.

Interchange-1 In the wafer inspection microscope apparatus according to the present invention, the inspection operation of the wafer surface by the objective optical system is performed by one-dimensional movement of the objective optical system, one-dimensional movement or rotational movement of the wafer inspection stage, or the optical axis of the eyepiece part of the objective optical system. The amount of change in the optical path length of the observation optical system is made as small as possible by rotational movement around the center.

Below, the present invention will be described in detail based on an embodiment shown in FIGS. 1 and 2. 1 is a sender in which a wafer cassette 2 is set, 3 is a wafer transport section, and 4 is a wafer cassette 5. The receiver 16 to which is set is the sender 1. Wafer transport section 3. A motor-driven conveyor belt 7 is provided in the receiver 4, a wafer inspection stage 1 is provided in the center of the wafer transfer section 3; It is a contact pre-alignment sensor, and the wafer inspection stage 7 is connected to the intake pipe 9.
It is connected to a vacuum pump (not shown) via a vacuum pump, and holds Ueno X10 placed on its upper surface by suction, and is also moved vertically and rotated in a horizontal plane by a stage drive position, which will be described later. There is. 11
is a first frame 12 disposed within the wafer transport section 3;
15 is a second frame mounted on the first frame 11 so as to be movable in the vertical direction via a roller guide 13, driven by a motor 14, and having the wafer inspection stage 7 pivotally mounted on the upper part; These gears are fixed to the central shaft and rotated by the motor 16 to rotate the wafer inspection stage 7 in a horizontal plane, and these gears constitute a stage drive device. Reference numeral 17 indicates an observation lens barrel fixed to a microscope main body (not shown) located close to the wafer transport section 3, and 18 indicates a direction perpendicular to the transport direction of the wafer 10 (arrow in FIG. The observation optical system including the objective lens 18 has an afocal structure in which the focal position does not change even if the optical path length is changed. , it is assumed that an image rotator is provided in the middle of the optical system.

Since the wafer inspection microscope apparatus according to the present invention is configured as described above, the wafer X10 in the wafer cassette 2 set in the sender 1 is conveyed to the wafer inspection stage 7 by the conveyor belt 6, and is then transferred to the wafer inspection stage by vacuum suction. 7 and is held by suction. Subsequently, the wafer inspection stage 7 is raised to the in-focus position by the stage drive device. Next, the wafer inspection stage 7 is rotated by the stage drive device, the orientation flat 10a of the wafer 10 is detected and positioned by the non-contact pre-alignment sensor 8, and then the wafer inspection stage 7 is inspected by the stage drive device to inspect the wafer 1. Rotate stage 7 further. On the other hand, in addition to this, the entire surface of the wafer X1 can be inspected using the objective lens 18 in a direction perpendicular to the wafer transport direction (in the direction of the arrow in FIG. 2, that is, in the radial direction of the wafer 10). At this time, the action of the image rotator prevents the image from rotating as the wafer 10 rotates, and a stationary image is always observed at the eyepiece of the inspection microscope. Further, in this example, the moving distance of the objective lens 18, that is, the amount of change in the optical path length of the observation optical system is R/2.

3 and 4 show a second embodiment, which is the same as the first embodiment in that the objective lens 18 is moved in a direction perpendicular to the transport direction (in the direction of the arrow in FIG. 2). However, the stage drive device is mounted on a first frame 11 disposed within the wafer transport section 3 and is mounted on the first frame 11 so as to be movable in the vertical direction via a roller guide 13 and is driven by a motor 14. A second frame 12' is mounted on the second frame 12' via a roller guide 17 so as to be movable in the same direction as the wafer conveyance direction (arrow direction in FIG. 2), and is driven by a motor 19. A third frame 20 on which a wafer inspection stage 7 is pivotally mounted
This embodiment differs from the first embodiment in that it is constructed from the above-mentioned components and can be assembled. Objective lens 18 in this example
The moving distance, that is, the amount of change in the optical path length of the observation optical system is R.

FIG. 5 shows a third embodiment, which is the same as the above two embodiments in that the objective lens 18 is moved in a -dimensional direction in a direction intersecting the transport direction (direction of arrow C in FIG. 5). However, the wafer inspection stage 7 is fixed and the objective lens 18 is fixed.
The distance it moves around the optical axis O of the eyepiece is the wafer 10.
It differs from the above two embodiments in that it is rotated by an angle θ corresponding to the diameter R of. In this example, the moving distance of the objective lens 18 in the direction of arrow C, that is, the amount of change in the optical path length of the observation optical system is R.

As mentioned above, the wafer inspection microscope device according to the present invention has the advantage that the entire device can be made compact, and
Since the amount of change in the optical path length of the Kanmine optical system is less than the diameter R of the wafer, which is significantly smaller than that of the conventional example, even if this microscope is an afocal system, the pupil is less likely to be eclipsed, so the imaging lens is relatively small. The movement of the eye point position of the eyepiece is also small.

[Brief explanation of drawings]

1 and 2 are a plan view and a perspective view, respectively, of an embodiment of a wafer inspection microscope apparatus according to the present invention, FIGS. 3 and 4 are a plan view and a perspective view, respectively, of a second embodiment, and FIG. The figure is a plan view of the main part of the third embodiment, and Figure 6 is an explanatory diagram showing the amount of change in the optical path length of the conventional observation optical system.・Wafer cassette,
3...Wafer transfer section, 4...Receiver-16.
...Transport belt, 7...°・Wafer inspection stage,
8...Non-contact pre-alignment sensor, 9...
・Intake pipe, lO...Wafer, 11...First frame, 12゜12'...Second frame, 13.17
...Roller guide, 14, 16.19...Motor, 15...Gear, 18...Objective lens, 20
...Continued from page 11 of the third frame) Inventor: Masami Kawasaki (within Hatagaya 2, Shibuya-ku, Tokyo) Inventor: Mori 1) Masa Akira Multiple occurrences within Hatagaya 2, Shibuya-ku, Tokyo (within 2 companies) Akira Takashi Nagano Hatagaya 2 company, Shibuya-ku, Tokyo

Claims (1)

[Claims] In a wafer inspection microscope device in which the objective optical system is moved along the top surface of the wafer, the operation of examining the wafer surface by the objective optical system involves the one-dimensional movement of the objective optical system and the one-dimensional movement or rotation of the wafer inspection stage. Alternatively, a wafer inspection microscope apparatus is characterized in that the rotational movement is performed around the optical axis of the eyepiece of an objective optical system.